The applicant proposed to provide an apparatus for placing a liquid crystal substrate, a plasma display substrate, or the like on a tray, and supplying it to a processing tool (Patent Publication 1: Japanese Laid-Open Patent Publication No. 2004-168483). The apparatus transports the tray using a conveyor, stores the tray in front of the processing tool, takes the substrate out of the tray, and supplies it to the processing tool.
In the case of supplying semiconductor wafers or the like to a processing tool, a plurality of the wafers are placed in one pod for transportation. If the wafers are not supplied to the processing tool timely, the efficiency of the processing tool becomes low. In particular, even if the number of wafers in the pod is different from the number of wafers processed at one time at the processing tool, it is necessary to supply the required number of wafers to the processing tool. In preparation for the case in which the order of arrival of pods is different from the order of priority in processing the wafers, a system for changing the order of supplying the wafers to the processing tool from the order of arrival of pods is required. Further, in some cases, the combination of wafers in the pod needs to be changed to match the next processing tool. Therefore, at the time of supplying the processed wafers to the pod, the system for changing combination of the wafers is required. In an attempt to solve the problem, the inventor conceived the present invention.